In the international press Nigeria is represented almost exclusively as a state in crisis. Recurrent military coups, ethnic and religious sectionalism, a civil war, a series of bloody riots and local unrest (of which the Niger delta situation is the best-known example), economic turmoil, and the re-imposition of the Islamic criminal code in many northern states have all been used to paint a picture of chaos and collapse. Journalists and government officials alike tend to find the roots of Nigeria's problems in intractable ethnic conflict, the collapse of oil prices in 1983, structural adjustment mandated by the International Monetary Fund in 1986, and hatred between Muslims and Christians. The trouble with Nigeria is also understood to illustrate the trouble with Africa. With 25 percent of the population of sub-Saharan Africa, Nigeria appears as representative of Africa. Potentially wealthy from its oil revenue, it symbolizes Africa's promise denied.